code: def _add_to_vocab(self, word):
      if word not in self._word2idx:
          idx = len(self._idx2word)
          self._idx2word[idx] = word
          self._word2idx[word] = idx
  
imports: import logging
  import json
  import numpy
  from collections import OrderedDict
  from .None import ontology
label_desc: Use image node_id 5 for calling the Vocab obj's underlying member method code with example usage: obj._add_to_vocab(word) without return types